New York suits Zac Posen. After two disappointing seasons showing in Paris, the designer returned home to knock everyone’s socks off. Gowns galore.

We wouldn’t be honest if we didn’t concede that expectations weren’t super high. As he got his start, Mr. Posen developed a reputation as a party boy who makes party dresses for party girls. But the magic came off his collections about the time of the financial crash. What’s more, he says he is actually a homebody.

Now he clearly has a new customer in mind for his namesake line (there’s the less expensive Z-Spoke for party girls.). The collections was all cocktail, evening and red carpet gowns. Look for one at the Oscars.

Surprise: Super model Coco Rocha is getting too big to walk on catwalks these days, but she tweeted earlier in the day that she would walk on only one New York runway—”Guess whose!” She opened Mr. Posen’s show with a figure hugging cocktail dress. (Mr. Posen made her wedding dress last year.)

Front row: Mom and Dad. Susan Posen was CEO of her son’s company until she stepped aside last year. She has clearly relinquished control. Looking rested, she said she hadn’t seen the collection until it went down the runway.

The Clothes: Mr. Posen’s gorgeous designs seemed destined for the opera or other fab galas—silks, embroidery, tons of frothy tulle sliced in at the waist and down at the neck, making even the models look curvy.